West Nile virus cases increase in US

In the USA some 241 cases of West Nile virus have been reported across 42 states so far during 2012, a figure higher compared with the previous year.

The US Center for Disease Control (CDC) has reported on the increase in cases of west Nile virus. Outbreaks for the disease typically occur in the summer months.

According to CDC figures the number of cases shows an increase, with the majority of incidents from Texas, Mississippi, and Oklahoma. In total eight deaths have been recorded. The reason for the upward trend remains unknown.

West Nile virus is type of virus known as a flavivirus. Researchers believe West Nile virus is spread when a mosquito bites an infected bird and then bites a person. Although 80% of cases are harmless, among the more serious incidents symptoms include abdominal pain, diarrhea, fever and headache.

"It is not clear why we are seeing more activity than in recent years. Regardless of the reasons for the increase, people should be aware we have West Nile virus in our state and take action to protect themselves and their family from mosquitoes.”

The first cases of West Nile virus were not reported in the US until 1999 (the disease is thought to have been transferred from Africa).